1. Technical Field
The present invention relates to an interactive projector capable of receiving an instruction on a projected screen by a pointing element of a user, and a system thereof.
2. Related Art
Patent Document 1 (JP-A-2012-150636) discloses a projection display apparatus (projector) capable of projecting a projected screen on a screen, and capturing an image containing an object such as a finger using a camera and detecting a position of the object using the captured image. The object such as a finger is used as a pointing element for giving an instruction on a projected screen. That is, the projector recognizes that a predetermined instruction of drawing or the like is input to the projected screen when the tip of the object is in contact with the screen, and redraws the projected screen according to the instruction. Therefore, a user can input various instructions using the projected screen as a user interface. As described above, the projector of the type capable of using the projected screen on the screen as an enterable user interface is called “interactive projector”. Further, the object used for giving an instruction on the projected screen is called “pointing element”.
In a typical interactive projector, whether or not an instruction is given by a pointing element is determined according to whether or not the tip of the pointing element is in contact with a screen. Therefore, detection of a distance between the tip of the pointing element and the screen is important. However, in related art, the detection accuracy of the distance between the tip of the pointing element and the screen is not necessarily sufficient and improvement of the detection accuracy is desired.